Manufacturing Unit 5, Lesson 2 Explanation Presentation © 2011 International Technology and Engineering Educators Association, STEM  Center for Teaching and Learning™ Foundations of Technology

The Unit Big Idea The designed world is the product of a design process, which provides ways to turn resources - materials, tools and machines, people, information, energy, capital, and time - into products and services. © 2011 International Technology and Engineering Educators Association, STEM  Center for Teaching and Learning™ Foundations of Technology

The Lesson Big Idea Manufacturing technologies produce quality goods at low prices, and apply the properties of materials to ensure the desired function of a product. © 2011 International Technology and Engineering Educators Association, STEM  Center for Teaching and Learning™ Foundations of Technology

Material Properties  The physical properties of the material are a basic reason for selecting the material  The performance of a product requires various behaviors and types of properties.  Example, a material could have particularly desirable electrical conductivity properties and perform poorly in maximum strength. © 2011 International Technology and Engineering Educators Association, STEM  Center for Teaching and Learning™ Foundations of Technology

Material Properties  Often a compromise/trade-off among the needed properties must be made  To be consistent with the processing selected  And the structural state desired or possible. © 2011 International Technology and Engineering Educators Association, STEM  Center for Teaching and Learning™ Foundations of Technology

Categories of Materials  Materials can be categorized as the following:  Metals  Ceramics  Plastics  Semiconductors  Composites © 2011 International Technology and Engineering Educators Association, STEM  Center for Teaching and Learning™ Foundations of Technology

Metals © 2011 International Technology and Engineering Educators Association, STEM  Center for Teaching and Learning™ Foundations of Technology  Materials that are normally combinations of metallic elements.  Elements, when combined, have electrons that are non-localized,  As a consequence, have generic types of properties.

Metals © 2011 International Technology and Engineering Educators Association, STEM  Center for Teaching and Learning™ Foundations of Technology  Metals are good conductors of heat and electricity.  Quite strong, but malleable  Lustrous look when polished.  Examples: copper, aluminum, titanium

Ceramics  Compounds between metallic and nonmetallic elements  Include such compounds as oxides, nitrides, and carbides.  They are insulating and resistant to high temperatures and harsh environments.  Examples: clay, tungsten carbide, alumina, glass © 2011 International Technology and Engineering Educators Association, STEM  Center for Teaching and Learning™ Foundations of Technology

Plastics & Polymers  Organic compounds based upon carbon and hydrogen.  Very large molecular structures.  Low density, not stable at high temperatures.  Two types:  Thermoset (can be melted and shaped once)  Thermoplastic (can be melted and reshaped)  Examples: nylon, polystyrene, rubber © 2011 International Technology and Engineering Educators Association, STEM  Center for Teaching and Learning™ Foundations of Technology

Semiconductors  Electrical properties intermediate between metallic conductors and ceramic insulators.  Electrical properties are strongly dependent upon small amounts of impurities.  Examples: silicon, germanium © 2011 International Technology and Engineering Educators Association, STEM  Center for Teaching and Learning™ Foundations of Technology

Composites  Composites consist of more than one distinct material type.  Examples: Fiberglass, a combination of glass and a polymer, concrete, plywood © 2011 International Technology and Engineering Educators Association, STEM  Center for Teaching and Learning™ Foundations of Technology

Reflection  Think about where you are sitting. What types of materials are surrounding you?  Is your computer, laptop, or cell phone made of more than one type of material? © 2011 International Technology and Engineering Educators Association, STEM  Center for Teaching and Learning™ Foundations of Technology

Properties of Materials  Properties of Materials can be categorized:  Mechanical  Electrical  Magnetic  Optical and Dielectric  Thermal © 2011 International Technology and Engineering Educators Association, STEM  Center for Teaching and Learning™ Foundations of Technology

Mechanical Properties  Tensile strength: measuring of resistance to being pulled apart  Fracture toughness: the ability of a material containing a crack to resist fracture  Fatigue strength: ability of material to resist various kinds of rapidly changing stresses  Creep strength: ability of a metal to withstand a constant weight or force at elevated temperatures  Hardness: property of a material to resist permanent indentation © 2011 International Technology and Engineering Educators Association, STEM  Center for Teaching and Learning™ Foundations of Technology

Electrical Properties  Conductivity: measure of how well a material accommodates the movement of an electric charge  Resistivity: opposition of a material to the flow of electrical current © 2011 International Technology and Engineering Educators Association, STEM  Center for Teaching and Learning™ Foundations of Technology

Magnetic Properties  Magnetic susceptibility : ratio of magnetization (M) to magnetic field (H)  Curie temperature : temperature at which a material will lose magnetism  Saturation magnetization: state reached when an increase in applied external magnetizing field H cannot increase the magnetization of the material further © 2011 International Technology and Engineering Educators Association, STEM  Center for Teaching and Learning™ Foundations of Technology

Thermal Properties  Coefficient of thermal expansion: how much a material will expand for each degree of temperature increase  Heat capacity: amount of heat required to change a material’s temperature by a given amount  Thermal conductivity: indicates a material’s ability to conduct heat © 2011 International Technology and Engineering Educators Association, STEM  Center for Teaching and Learning™ Foundations of Technology

Manufacturing  How do we apply the properties of materials?  Engineers use the material properties to select appropriate materials for product production. © 2011 International Technology and Engineering Educators Association, STEM  Center for Teaching and Learning™ Foundations of Technology

Manufacturing Processes  Primary processes  Turn raw materials into standard stock (timber cut into boards)  Secondary processes  Turn standard stock into finish products (boards turned into furniture) © 2011 International Technology and Engineering Educators Association, STEM  Center for Teaching and Learning™ Foundations of Technology

Manufacturing Types  Final manufactured Products can be one of three types:  Custom  Batch  Continuous © 2011 International Technology and Engineering Educators Association, STEM  Center for Teaching and Learning™ Foundations of Technology

Custom Manufacturing  One of kind item made by a specialist  Product examples: yacht, clothing, purse © 2011 International Technology and Engineering Educators Association, STEM  Center for Teaching and Learning™ Foundations of Technology

Batch Manufacturing  Products are made in batches.  The components of a product are completed at a workstation before they move to the next one.  Product Examples: bakery items, paints, special edition shoes © 2011 International Technology and Engineering Educators Association, STEM  Center for Teaching and Learning™ Foundations of Technology

Continuous Manufacturing  Products are made with no interruption to the production line from the input to output.  Product examples: cars, food products, bricks © 2011 International Technology and Engineering Educators Association, STEM  Center for Teaching and Learning™ Foundations of Technology

Interchangeable Parts  The invention of interchangeable parts in the 1700s innovated manufacturing.  Interchangeable parts are parts that are identical, meaning to replace the part, you do not have to make a custom piece. There is already one the same size. © 2011 International Technology and Engineering Educators Association, STEM  Center for Teaching and Learning™ Foundations of Technology

Interchangeable Parts  The interchangeability of parts increased the effectiveness of all manufacturing processes.  An example would be a windshield wiper blade that can be used on multiple vehicle models. © 2011 International Technology and Engineering Educators Association, STEM  Center for Teaching and Learning™ Foundations of Technology